//随着屏幕大小变化  html字体大小改变    
(function (doc, win) {
        var docEl = doc.documentElement,
                resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize',
                recalc = function () {
                    var clientWidth = docEl.clientWidth;
                    if (!clientWidth) return;
                    if(clientWidth>=750){
                        docEl.style.fontSize = '100px';
                    }else{
                        docEl.style.fontSize = 100 * (clientWidth / 750) + 'px';
                    }
                };
        if (!doc.addEventListener) return;
        win.addEventListener(resizeEvt, recalc, false);
        doc.addEventListener('DOMContentLoaded', recalc, false);
	recalc();
})(document, window);